Change the handling of catch blocks to use context extension objects...

src/usage-analyzer.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 51 matching lines @@
   void VisitFunctionLiteral(FunctionLiteral* node);
   void VisitFunctionBoilerplateLiteral(FunctionBoilerplateLiteral* node);
   void VisitConditional(Conditional* node);
   void VisitSlot(Slot* node);
   void VisitVariable(Variable* node);
   void VisitVariableProxy(VariableProxy* node);
   void VisitLiteral(Literal* node);
   void VisitRegExpLiteral(RegExpLiteral* node);
   void VisitObjectLiteral(ObjectLiteral* node);
   void VisitArrayLiteral(ArrayLiteral* node);
+  void VisitCatchExtensionObject(CatchExtensionObject* node);
   void VisitAssignment(Assignment* node);
   void VisitThrow(Throw* node);
   void VisitProperty(Property* node);
   void VisitCall(Call* node);
   void VisitCallEval(CallEval* node);
   void VisitCallNew(CallNew* node);
   void VisitCallRuntime(CallRuntime* node);
   void VisitUnaryOperation(UnaryOperation* node);
   void VisitCountOperation(CountOperation* node);
   void VisitBinaryOperation(BinaryOperation* node);
@@ skipping 199 matching lines @@
 void UsageComputer::VisitObjectLiteral(ObjectLiteral* node) {
   ReadList(node->properties());
 }
 
 
 void UsageComputer::VisitArrayLiteral(ArrayLiteral* node) {
   ReadList(node->values());
 }
 
 
+void UsageComputer::VisitCatchExtensionObject(CatchExtensionObject* node) {
+  Read(node->value());
+}
+
+
 void UsageComputer::VisitAssignment(Assignment* node) {
   if (node->op() != Token::ASSIGN)
     Read(node->target());
   Write(node->target());
   Read(node->value());
 }
 
 
 void UsageComputer::VisitThrow(Throw* node) {
   Read(node->exception());
@@ skipping 134 matching lines @@
 
 // ----------------------------------------------------------------------------
 // Interface to variable usage analysis
 
 bool AnalyzeVariableUsage(FunctionLiteral* lit) {
   if (!FLAG_usage_computation) return true;
   return UsageComputer::Traverse(lit);
 }
 
 } }  // namespace v8::internal